Field of the Invention
The present invention relates to a fiber optic connector and a method of assembling the fiber optic connector.
Description of the Related Art
In prior art, optical cables/fibers generally are optically coupled by following ways of:
1) Splicing Optical Fibers in Field
The way of splicing the optical cables/fibers generally comprises steps of: Firstly, processing ends of the optical fibers (including peeling off the optical cable, cleaning and cutting the optical fiber of the optical cable); Secondly, manually or automatically setting optimum splicing parameters of a splicing machine and relative positions of the optical fibers to be spliced based on material and type of the optical fiber; Thirdly, discharging an electric arc with the splicing machine to fuse the ends of the optical fibers, and slowly and linearly pushing the optical fibers toward each other to optically couple the optical fibers; Finally, contracting a heat shrinkable tube on a coupled joint of the optical fibers to protect the coupled joint, and winding the optical fibers to finish all splicing operations in the field. In this case, the splicing properties (including optical attenuation, echo, and long term reliability, etc.) of the optical fibers are in different degrees depended on various factors, such as, operation level of a splicing operator, operation steps, fiber winding level, cleanliness of electrodes of the splicing machine, splicing parameters, cleanliness of working environment, and so on. In addition, it is necessary to use various expensive apparatus, for example, high precision cutting tool, splicing machine or the like, to perform the splicing of the optical fibers in the field.
2) Cold Coupling Optical Fibers
In this solution, two processed optical fibers are fixed in a high precision V-shaped or U-shaped groove and aligned to each other. In addition, an optical matching paste is filled in the V-shaped or U-shaped groove to fill a gap between end surfaces of the two optical fibers. Compared with splicing, the cold coupling is relatively simpler and quicker, because the cold coupling does not need an electric power supply and a heat shrinkable tube to protect the spliced joint. However, the cold coupling is largely depended on cutting quality of the end surfaces of the optical fibers and the optical matching paste. If the cutting quality is poor, it decreases the coupling properties (including optical attenuation, echo, and long term reliability, etc.). Furthermore, as for the cold coupling with the V-shaped or U-shaped groove, the coupling loss is increased with the variation of the temperature. With the passage of time, because of the opened V-shaped or U-shaped groove, flowing away, pollution and aging occurring in the optical matching paste may cause the insertion loss to become larger or even reduce the optical signal to zero. Thereby, the cold coupling has a poor stability and long-term reliability.
3) Assembling Connector in Field
In the way of assembling connector in field, an optical fiber is pre-embedded in a ferrule. At one end of ferrule, an end surface of a standard connector is pre-polished, and at the other end of the ferrule, the pre-embedded fiber is placed in a high precision V-shaped groove with an optical matching paste filled therein. During assembling the connector in the field, the incoming optical fiber/cable is processed in the field (for example, opening the cable, peeling the fiber, cleaning and cutting the fiber), and inserted into the rear end of the connector until the end surface of incoming fiber abuts against the end surface of the pre-embedded fiber in the V-shaped or U-shaped groove, then the fibers are fixed by an external mechanical element. The way of assembling connector in field has a relatively high cost. In addition, it is necessary to use a special tool and an operation guide provided by the connector manufacturer. Also, because the optical matching paste is used, it has a poor stability and long-term reliability.
4) Integral Cable/Fiber Assembly in Factory
The integral cable/fiber assembly is manufactured in the factory. As for this way, it is reliable and is easy to use. However, it cannot be applied in a limited space, for example, in an application of fiber to the home or to the resident, it often needs to pull the cable/fiber assembly through a narrow pipe, especially a pipe in which other cables are paved.
In the above ways in the prior art, there are high requirements on the tool and the operator to assemble the connector in the field. Furthermore, in the prior art, before assembling a ferrule assembly, a spring and a spring seat into the connector housing, the ferrule assembly, the spring and the spring seat are separated from each other and cannot be pre-assembled together. Thereby, in the prior art, the ferrule assembly, the spring and the spring seat must be assembled into the connector housing one by one. Such way of assembling the connector is only adapted to assemble the ferrule assembly, the spring and the spring seat into the connector housing in the factory, and is not adapted to assemble the ferrule assembly, the spring and the spring seat into the connector housing in the field. As a result, the completely assembled connector in the factory cannot be pulled through the narrow pipe in the field, because the completely assembled connector has a large profile size.